A GHOST is an event that is a duplicate reflection caused by light bouncing back and forth between connectors. It is caused by a dirty, scratched, cracked, misaligned, or unseated connector. Bad connectors should be cleaned, re-polished, or replaced.
Here is an example of a typical ghost (minus the animation!).
OptiFiber can identify which connector is causing the ghost. At 164 ft, the connector loss is very high @ 2.70 dB; it should be better than 0.75 dB.
A quick way of detecting a ghost is to measure the loss. We have zoomed in on the suspected ghost event from above:
A characteristic of a ghost, is that the event has a loss of 0 dB, as in this case.